The subtraction property of equality: if we subtract one side of the equation then we also must subtract from the other side of the equation.
The division property of equality: if we divide one side of the equation by a number then we also must divide the other side by the same number.
For this equation:
3 x + 5 = 26
3 x + 5 - 5 = 26 - 5        ( the Subtraction Property of Equality )
3 x = 21
3 x : 3 = 21 : 3       ( the Division Property of Equality )
x = 7
Answer: C ) The standard method for solving an equation like 3 x + 5 = 26 is to use the Subtraction Property of Equality and then the Division Property of Equality.  
        
                    
             
        
        
        
Answer:
287 books
Step-by-step explanation 
there was already 239 books. when the problem mentoins that Mary ADDS MORE books to the shelf, the operation is addition. 
239+48=287
 
        
             
        
        
        
Answer:
Step-by-step explanation:
1000 Ohms
R = 1000
V = 9
I = V / R 
I = 9 / 1000
I = 0.009
500000 Ohms
V = 9
I = V/R
R = 500000
I = 9 / 500000
I = 0.000018